Nanotechnology: South Africa: New Lab to Help Combat Deadly Diseases; Clean Water; Renewable Energy


South Africa II nanotechnology-india-brazil_26Science and Technology Minister Naledi Pandor yesterday unveiled a R30 million “cleanroom” facility at Mintek’s Nanotechnology Innovation Centre (NIC) in Johannesburg.

The facility allows for the manufacture of devices that permit the rapid diagnosis of illnesses such as malaria.

The department explained that so-called cleanrooms are essential for the fabrication and production of advanced devices and systems that require the concentration of airborne particles to be controlled to ensure that processes are not compromised by unwanted and/or unknown contaminants.South Africa Department-of-Science-and-Technology-DST

Cleanrooms also allow the control of other variables, such as temperature, humidity and pressure.

Commissioned by the department last December, the facility is designed to enable the NIC and South Africa’s researchers to develop and fabricate nanotechnology-based diagnostic devices and tools for application in health and the containment of biological reagents.

The facility will also enable the centre to produce nanotechnology-based devices and systems that meet the most stringent International Standards Organisation requirements.

According to the department, this makes it possible for the NIC to follow good manufacturing practice guidelines and comply with pharmaceutical inspection conventions and cooperation.

Unveiling the facility, Minister Pandor said the department was greatly encouraged by the progress government had made since the launch of the National Nanotechnology Strategy in 2005.

South Africa NIC banner-06022012-300x165“When we launched the strategy, we set ourselves ambitious goals in respect of the provision of clean water, clean and reliable energy, and improved health care. We are committed to doing this cost-effectively, and we remain committed to these goals and focused on their realisation,” said Minister Pandor.

The Minister added that reliable research equipment and research chairs in the field would enhance the generation of nanotechnology knowledge and nanotechnology innovation in South Africa. – SAnews.gov.za

New source of cells for modeling malaria


MIT-Malaria-Liver-01_0x250In 2008, the World Health Organization announced a global effort to eradicate malaria, which kills about 800,000 people every year. As part of that goal, scientists are trying to develop new drugs that target the malaria parasite during the stage when it infects the human liver, which is crucial because some strains of malaria can lie dormant in the liver for several years before flaring up.

A new advance by Massachusetts Institute of Technology (MIT) engineers could aid in those efforts: The researchers have discovered a way to grow liver-like cells from induced pluripotent stem cells. These cells can be infected with several strains of the malaria parasite and respond to existing drugs the same way that mature liver cells taken from human donors do.

Such cells offer a plentiful source for testing potential malaria drugs because they can be made from skin cells. New drugs are badly needed, since some forms of the malaria parasite have become resistant to existing treatments, says Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology (HST) and Electrical Engineering and Computer Science at MIT.

“Drug resistance is emerging that we are continually chasing. The thinking behind the call to eradication is that we can’t be chasing resistance and distributing bed nets to protect from mosquitoes forever. Ideally, we would rid ourselves of the pathogen entirely,” says Bhatia, who is also a member of MIT’s Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science (IMES).

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MIT researchers engineered liver-like cells that can be infected with several strains of the parasite that causes malaria, including Plasmodium falciparum (top row) and Plasmodium berghei (bottom row). The red stain reveals parasite infection. Courtesy of the researchers

These cells, described in an online issue of Stem Cell Reports, could also allow scientists to test drugs on cells from people with different genetic backgrounds, who may respond differently to malaria infection and treatment.

The paper’s lead author is Shengyong Ng, a graduate student in MIT’s Dept. of Biological Engineering and IMES. Other authors of the paper are former IMES postdoctoral researcher Robert Schwartz; MIT research scientist Sandra March; IMES research technician Ani Galstian; HST graduate students Nil Gural and Jing Shan; former IMES research technician Mythili Prabhu; and Maria Mota, a researcher at the Instituto de Medicina Molecular in Portugal.

Modeling infection
Until now, malaria researchers have not had many reliable ways to test new drugs in liver tissue. “What’s historically been done is people have tried to make do with the systems that were available,” Bhatia says.

Those systems include testing drugs in cancerous liver cells or in mice infected with a rodent-specific version of the malaria parasite. However, cancerous cells divide much more frequently than normal adult liver cells, and are missing some of the genes required for drug metabolism. The mouse model is not ideal because the rodent version of malaria is different from the human one, so drugs that are successful in mice don’t always work in humans.

In 2013, Bhatia and colleagues showed that they could mode malaria infection in adult liver cells, known as hepatocytes, taken from human donors. However, this generates only a limited supply from each donor, and not all of the cells work well for drug studies.

The researchers then turned to induced pluripotent stem cells. These immature cells can be generated from human skin cells by adding several genes known as reprogramming factors. Once the cells are reprogrammed, they can be directed to form differentiated adult cells by adding specific growth factors.

To create liver cells, the researchers added a series of growth factors, including hepatocyte growth factor. Working with Charles Rice of Rockefeller Univ. and Stephen Duncan of the Medical College of Wisconsin, Bhatia’s lab generated these cells in 2012 and used them to model infection of hepatitis C. However, these cells, known as hepatocyte-like cells, did not seem to be as mature as real adult liver cells.

In the new study, the MIT team found that these cells could be infected with several strains of malaria, but did not have the same drug responses as adult liver cells. In particular, they were not sensitive to primaquine, which works only if cells have a certain set of drug-metabolism enzymes found in mature liver cells. This is important because primaquine is one of only two drugs approved to treat liver-stage malaria, and many of the drugs now in development are based on primaquine.

To induce the cells to become more mature and turn on these metabolic enzymes, the researchers added a molecule they had identified in a previous study. This compound, which the researchers call a “maturin,” stimulated the cells to turn on those enzymes, which made them sensitive to primaquine treatment.

The MIT team is now working with the nonprofit foundation Medical Malaria Ventures to test about 10 potential malaria drugs that are in the pipeline, first using adult donor liver cells and then the hepatocyte-like cells generated in this study.

These cells could also prove useful to help identify new drug targets. In this study, the researchers found that the liver-like cells can be infected with malaria when they are still in the equivalent of fetal stages of development, when they become cells known as hepatoblasts, which are precursors to hepatocytes.

In future studies, the researchers plan to investigate which genes get turned on at the point when the cells become susceptible to infection, which may suggest new targets for malaria drugs. They also hope to compare the genes needed for malaria infection with those needed for hepatitis infection, in hopes of identifying common pathways to target for both diseases.

Source: Massachusetts Institute of Technology

Using Nanotechnology Against Malaria Parasites


Malaria 6-nanotechnoloMalaria parasites invade human red blood cells, they then disrupt them and infect others. Researchers at the University of Basel and the Swiss Tropical and Public Health Institute have now developed so-called nanomimics of host cell membranes that trick the parasites. This could lead to novel treatment and vaccination strategies in the fight against malaria and other infectious diseases. Their research results have been published in the scientific journal ACS Nano.

For many infectious diseases no vaccine currently exists. In addition, resistance against currently used drugs is spreading rapidly. To fight these diseases, innovative strategies using new mechanisms of action are needed. The Plasmodium falciparum that is transmitted by the Anopheles mosquito is such an example. Malaria is still responsible for more than 600,000 deaths annually, especially affecting children in Africa (WHO, 2012).

Artificial bubbles with receptors

Malaria parasites normally invade human red in which they hide and reproduce. They then make the host cell burst and infect new cells. Using nanomimics, this cycle can now be effectively disrupted: The egressing parasites now bind to the nanomimics instead of the red blood cells.

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Researchers of groups led by Prof. Wolfgang Meier, Prof. Cornelia Palivan (both at the University of Basel) and Prof. Hans-Peter Beck (Swiss TPH) have successfully designed and tested host cell nanomimics. For this, they developed a simple procedure to produce polymer vesicles – small artificial bubbles – with host cell receptors on the surface. The preparation of such polymer vesicles with water-soluble host receptors was done by using a mixture of two different block copolymers. In aqueous solution, the nanomimics spontaneously form by self-assembly.

Blocking parasites efficiently

Usually, the malaria parasites destroy their host cells after 48 hours and then infect new . At this stage, they have to bind specific host cell receptors. Nanomimics are now able to bind the egressing parasites, thus blocking the invasion of new cells. The parasites are no longer able to invade host cells, however, they are fully accessible to the immune system.

The researchers examined the interaction of nanomimics with malaria parasites in detail by using fluorescence and electron microscopy. A large number of nanomimics were able to bind to the parasites and the reduction of infection through the nanomimics was 100-fold higher when compared to a soluble form of the host cell receptors. In other words: In order to block all , a 100 times higher concentration of soluble host is needed, than when the receptors are presented on the surface of nanomimics.

“Our results could lead to new alternative treatment and vaccines strategies in the future”, says Adrian Najer first-author of the study. Since many other pathogens use the same receptor for invasion, the nanomimics might also be used against other . The research project was funded by the Swiss National Science Foundation and the NCCR “Molecular Systems Engineering”.

Explore further: Why humans don’t suffer from chimpanzee malaria

More information: Adrian Najer, Dalin Wu, Andrej Bieri, Françoise Brand, Cornelia G. Palivan, Hans-Peter Beck, and Wolfgang Meier. “Nanomimics of Host Cell Membranes Block Invasion and Expose Invasive Malaria Parasites.” ACS Nano, Publication Date (Web): November 29, 2014 | DOI: 10.1021/nn5054206

Patent awarded for genetics-based nanotechnology against mosquitoes, insect pests


1-dnaguidedassKansas State University researchers have developed a patented method of keeping mosquitoes and other insect pests at bay.

U.S. Patent 8,841,272, “Double-Stranded RNA-Based Nanoparticles for Insect Gene Silencing,” was recently awarded to the Kansas State University Research Foundation, a nonprofit corporation responsible for managing technology transfer activities at the university. The patent covers microscopic, genetics-based technology that can help safely kill mosquitos and other .

Kun Yan Zhu, professor of entomology; Xin Zhang, research associate in the Division of Biology; and Jianzhen Zhang, visiting scientist from Shanxi University in China, developed the technology: nanoparticles comprised of a nontoxic, biodegradable polymer matrix and insect derived double-stranded ribonucleic acid, or dsRNA. Double-stranded RNA is a synthesized molecule that can trigger a biological process known as RNA interference, or RNAi, to destroy the genetic code of an insect in a specific DNA sequence.

The technology is expected to have great potential for safe and effective control of insect pests, Zhu said.

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“For example, we can buy cockroach bait that contains a toxic substance to kill cockroaches. However, the bait could potentially harm whatever else ingests it,” Zhu said. “If we can incorporate dsRNA specifically targeting a cockroach gene in the bait rather than a , the bait would not harm other organisms, such as pets, because the dsRNA is designed to specifically disable the function of the cockroach gene.”

Researchers developed the technology while looking at how to disable gene functions in mosquito larvae. After testing a series of unsuccessful genetic techniques, the team turned to a nanoparticle-based approach.

Once ingested, the nanoparticles act as a Trojan horse, releasing the loosely bound dsRNA into the insect gut. The dsRNA then triggers a genetic chain reaction that destroys specific messenger RNA, or mRNA, in the developing insects. Messenger RNA carries important genetic information.

In the studies on mosquito larvae, researchers designed dsRNA to target the mRNA encoding the enzymes that help mosquitoes produce chitin, the main component in the hard exoskeleton of insects, crustaceans and arachnids.

Researchers found that the developing mosquitoes produced less chitin. As a result, the mosquitoes were more prone to insecticides as they no longer had a sufficient amount of chitin for a normal functioning protective shell. If the production of chitin can be further reduced, the insects can be killed without using any toxic insecticides.

While mosquitos were the primary insect for which the nanoparticle-based method was developed, the technology can be applied to other insect pests, Zhu said.

“Our dsRNA molecules were designed based on specific gene sequences of the mosquito,” Zhu said. “You can design species-specific dsRNA for the same or different genes for other insect pests. When you make baits containing gene-specific nanoparticles, you may be able to kill the insects through the RNAi pathway. We see this having really broad applications for insect pest management.”

Explore further: Protein found in insect blood that helps power pests’ immune responses